Pam,
I too am aflicted with the "can't shut down in os 10.1.2 no matter what" on my dual 1Ghz Quicksilver. I also have a 2001 iBook, both with 10.1.2, and both with the Norton beta, but I can shut down my iBook.
Any luck talking to Apple? I wanna put my foot through the wall over this one...